This injury occurred on a combined U.S. and Australian special operations mission in the mountains of southern Afghanistan a few years back. The case study is one I used some photos from in my previous post, “Why I’d rather be shot by an AK-47 than an M4.” After that post, I had multiple emails requesting further information about this case study and how he was medically managed. So here it is.
The casualty in question was, in fact, an enemy combatant, which explains how he came to be shot with an M4 (another point that I received a few questions about from my previous post). During the firefight on that day, the casualty was hit by a single M4 round from a range of approximately 150 meters. The bullet entered through his right lower buttock and exited out his right upper thigh. Unbeknownst to the medic who initially reviewed the casualty at point of injury, the bullet had struck the casualty’s upper femur, disintegrating and shattering the bone, which in turn created multiple secondary missiles in the form of bone fragments.
As the enemy combatant was incapacitated by the wound, he was no longer considered a threat and therefore, in accordance with the Geneva Convention, was to be afforded the same medical care as one of our own. On initial review, the treating medic noted the massive lateral thigh wound to be bleeding significantly, but assessed the wound as being too high for effective arterial tourniquet placement. He therefore opted for the use of a hemostatic dressing, which in those days came in the form of a QuikClot advanced clotting sponge (ACS). For those of you who weren’t around in the days prior to QuikClot combat gauze, the ACS was a precursor dressing to the combat gauze, and consisted of a teabag-like structure filled with small granules of hemostatic dressing.
The medic at point of injury packed an ACS into the wound and then applied a pressure dressing over the top, effectively stopping the bleeding. One downside to the ACS, which has been solved with the combat gauze, was that it was thermogenic when it contacted blood, and would often cause significant additional pain to the casualty as it burned, as well as damaging tissues in direct contact to it. The operation was nearing completion at the time the casualty was hit, so rather than call for a dust-off bird, the casualty was extracted back to the forward surgical team (FST) with the ground force.
Once initial resuscitation of the casualty had been performed at the FST, I cut the pressure dressing off the casualty’s thigh to find the following:
The granular material seen in the centre of the wound is the ACS. The dark red/brown tissue surrounding the wound is devitalised tissue that has been damaged either by the trauma of the bullet itself, or burned by the ACS as it generated heat during activation. As can be seen in the image above, there was minimal ongoing bleeding from the wound at time of review at the FST.
The corresponding entrance wound was also reviewed and appeared as follows:
This photo was taken only about an hour or so after the injury was sustained, but the huge amount of bruising surrounding the bullet entrance hole can be seen already. This bruising was due to tissue damage caused by the pressure wave that emanated out from the path of the bullet as it passed through the tissues. This pressure wave creates something known as temporary cavitation. The projectile, rapidly slowing down in the tissues, dissipates its energy into them. This pressure wave pulverizes tissues and ruptures small blood vessels, causing extensive bruising. Further discussion on temporary cavitation can once again be found in my previous post, “Why I’d rather be shot by an AK-47 than an M4.”
As with any limb injury, a high priority was to assess for blood flow distal to the wound in order to ascertain if the major blood vessels had been damaged. Remarkably, the casualty had normal blood flow to his feet, implying that the femoral artery was intact. Next came an X-ray to have a look at the underlying bone structures. The casualty had minimal movement in the leg at time of review, and we expected him to have a fracture of his femur underlying the injury. The following images of the X-ray highlight the main features, including the shattered femur from where the bullet struck, the bullet fragments from where the projectile had disintegrated on impact, and the granular material of the ACS.
The following image is of an angiogram procedure where dye—visible on X-ray—is injected into a patient, and then X-rays are taken to outline the blood vessels. The vessels seen in the image are the main branches of the femoral artery as it passes the region where the casualty was shot. When you look at where the femoral artery runs, and then look again at the damage done to the casualty’s femur, it is remarkable that the artery was not severed.
Once we were comfortable that the casualty was medically stable enough to go to surgery, he was wheeled through to the operating theatre where we prepared him for his initial wound surgery. The priorities in the FST setting were to perform a procedure known as a debridement, which is the removal of any dead tissue that is likely to cause infection if left in place, as well as stabilization of any fractures. For the latter, a technique know as external fixation is used frequently in the context of war wounds. In external fixation, a series of surgical screws are drilled into the good bone above and below the fractured area, and then an external frame is constructed to stabilize the fracture.
This series of images shows the hardware being placed into the good bone above the fracture site, with the first image showing the manual drill used for the process in the FST setting. The following images show the placement of the screws into the good bone below the fracture site, with an illustration of their location on the X-ray image. The device, covered in plastic and hovering over the surgical site, is an X-ray image intensifier, which allows real-time X-ray images to be viewed on a screen in order to assists surgeons during operative procedures with hardware placement and other interventions. In the second image below, it can be seen that the wound has been debrided of all the dead, dark red and brown tissues, leaving bright red, healthy-looking tissues.
Once the pins had been appropriately placed above and below the fracture site, the femur was pulled back out to its appropriate length and stabilized with external rods bolted onto the screws in the bones. The various pieces of shattered femur that can be seen in the X-ray images were all put back in their rightful place with the hope that they would heal back together as any other fractured bone does.
No attempt is made at the time of initial wound surgery to close a wound like this, as it will require multiple additional surgeries over a period of weeks to debride additional dead tissue missed in the initial debridement, or that has died subsequent to the initial surgery. At the time when closure is appropriate for a large wound like this, it is likely that extensive skin grafting would be necessary to cover suck a large deficit.
In the instance of the casualty in this case study, the wound was packed and dressed, and the patient was prepared for aero-medical evacuation to the next level of care.
Owing to the limited ability to hold and care for post-operative patients at the FST, coupled with the requirement to make way for the steady flow of trauma casualties that came through the facility daily, this casualty was on a bird out of there the afternoon of his surgery. Complicating matters in his instance was the fact that he was an enemy combatant, and as such required a security escort as well as medical escort to his destination medical facility.
I lost track of him from that day on, so unfortunately I don’t know how the story ended, or whether he kept the leg or not. What I do know is that the treatment he received from point of injury through to initial wound surgery was first rate, and was a credit to the pre-hospital medic and a tribute to the skill of the anesthetists and surgeons at the FST. The fact that he received that level of treatment despite being an enemy combatant is a testament to the integrity of the coalition forces, and what separates us from others.
As always, questions and comments are welcome. Thanks for reading.